MINNEAPOLIS — From the beginning, the death of George Floyd disrupted the field of forensic pathology in much the way it challenged policing.
Days after Mr. Floyd’s death on May 25, prosecutors said it was caused not just by the police officer kneeling on his neck for nine minutes and 29 seconds, but also by his underlying health conditions and drug use.
Critics protested that the finding reflected racial bias — and served as a prime example of how forensic pathology has failed to do enough to counter its own subjectivity in decisions such as whether to classify a death in police custody as a homicide.
The public criticism helped expose long-simmering tensions within the small but influential world of medical examiners, drawing in some of the experts who consulted on the case and may be called to testify for the defense.
Some of them have vigorously objected to a study, published just before the trial began, that measured bias among forensic pathologists, taking the unusual step of asking that it be retracted.
The timing of the paper was “particularly alarming in the era of Black Lives Matter, critical race theory, riots and so forth,” wrote Dr. Brian L. Peterson, the Milwaukee County medical examiner, in one of several emails to a private forensic pathology email list obtained by The New York Times. “What is woke today is fodder tomorrow.”
Medical examiners say that of course they, like everyone else, have biases — but that they already have ample systems in place, including courtroom scrutiny of their decisions, to curb them. In fact, Dr. Peterson wrote, the notion that cause-of-death determinations are objective and science-based is “basically nonsense.”
“Is there anyone in our profession that has not, at one point or another, quipped about ‘spinning the wheel of death’ and picking one?”
After the Journal of Forensic Sciences published the study, which showed that medically irrelevant information like the victim’s race can sway the decisions of forensic pathologists, Dr. Peterson, along with Dr. David Fowler and Dr. William Oliver, signed a letter asking that it be retracted, calling it “fatally flawed.”
The Journal of Forensic Sciences, which published the paper, declined to retract it.
Dr. Fowler, who testified on Wednesday for Mr. Chauvin’s defense, is the former chief medical examiner of Maryland, and Dr. Oliver is a professor at the Brody School of Medicine in North Carolina. Dr. Fowler is named in a civil rights lawsuit filed by the family of Anton Black, an unarmed Black teenager who died in Baltimore in 2018 after officers held him down in the prone position for about six minutes. Dr. Fowler’s office classified the death as an accident.
Complaints of bias have long hung over the Floyd case. Four days after Mr. Floyd’s death, the county prosecutors listed what they said were preliminary autopsy findings in a criminal complaint that many said undermined their own case against the officers involved.
An opinion piece written by 12 doctors and published in Scientific American called the complaint “a weaponization of medical language” that “reinforced white supremacy at the torment of Black Americans.”
“They took standard components of a preliminary autopsy report to cast doubt, to sow uncertainty; to gaslight America into thinking we didn’t see what we know we saw,” they wrote.
The state attorney general, Keith Ellison, soon took over the case.
By then the Floyd family had hired two forensic pathologists, a white man and a Black woman, to conduct their own autopsies. Both of them, Dr. Michael Baden and Dr. Allecia Wilson, said that asphyxia, or deprivation of oxygen, was the cause of death and placed the blame squarely on the police officers involved.
April 14, 2021, 2:57 p.m. ET
Second autopsies have long been a common practice, in part because medical examiners have longstanding relationships with prosecutors and the police, raising concerns about their objectivity in deaths involving officers.
But in Mr. Floyd’s case the main professional organization for forensic pathologists, the National Association of Medical Examiners, took the unusual step of issuing a statement that many perceived as critical of the practice.
The association’s primary goal seemed to be to defend Dr. Andrew Baker, the Hennepin County medical examiner and a past president of the association, who performed the Floyd autopsy.
After his report, which classified the death as a homicide and listed heart disease, fentanyl and methamphetamine as contributing factors to Mr. Floyd’s death, was released last June, an emergency fence and concrete barricades were erected around his office.
The statement from the association took issue with news reports that described the private autopsies by Drs. Baden and Wilson as “independent,” implying that Dr. Baker’s was compromised.
“The independent autopsy is the one done by the medical examiner who, unlike private pathologists, do not have an incentive to come up with a certain view,” it said.
But private autopsies are a routine stream of income for many forensic pathologists, and the association began to receive complaints, including one from one of the country’s most renowned forensic pathologists, Cyril Wecht. Another came from Dr. Wilson, one of the pathologists hired by the Floyd family.
“Our fight should not be between each other but working together to understand why Black men are dying so quickly when taken into police custody,” Dr. Wilson wrote, saying the Floyd family’s consulting with her was akin to a patient’s getting a second opinion. She noted that the practice had never before earned a rebuke from the association.
“I am particularly offended as I have watched Dr. Baden make controversial opinions my entire career, but when another, a Black woman, has a controversial opinion, it is handled quite differently,” she wrote.
The medical examiners association retracted the statement.
Its leaders also invited Dr. Joye Carter to help develop a protocol for second autopsies. Dr. Carter says she is the first Black woman to be board certified in forensic pathology in the United States and the first Black person appointed to be a chief medical examiner, a position she held in Washington, D.C., and Houston. She consulted on the Floyd case for the prosecution.
Dr. Carter had discontinued her membership in the national association five years before. “I never felt welcome. I never felt included,” she said. “You know, there’s a difference between feeling welcomed and feeling tolerated.”
She agreed to come back and was hopeful that things had changed, especially after she was asked to chair a new diversity committee.
Because of that, she said, she did not anticipate any controversy when she signed on to the study on bias among forensic pathologists, led by Itiel Dror, a cognitive neuroscientist who specializes in expert error and bias. The authors examined 10 years of children’s death certificates in Nevada and found that the deaths of Black children were a little more likely to be classified as homicides, rather than accidents, compared with deaths of white children.
They also sent a death scenario to forensic pathologists, and found that those who responded were more likely to rule it a homicide when the child in the scenario was Black and cared for by the mother’s boyfriend than when the child was white and cared for by a grandmother.
The authors said the study was merely a starting point for research and suggested that forensic pathologists further explore how and when contextual information should be used, and be transparent when using it.
Four of the study’s authors were forensic pathologists, including Dr. Carter.
In February, Dr. Peterson, the potential defense witness in Mr. Floyd’s case, filed an ethics complaint against all four, accusing them of “conduct averse to the best interests and purposes” of the profession.
“By basically accusing every member of ‘unconscious’ racism, a charge impossible to either prove or refute, members will henceforth need to confront this bogus issue whenever testifying in court,” he wrote in the complaint, a copy of which was obtained by The Times.
Dr. Peterson did not respond to a message left with his office, where a spokeswoman said he was on vacation. Ethics complaints are supposed to be confidential, and the accused doctors declined to discuss it or did not respond to a request for comment.
The vitriolic response to the study surprised Dr. Carter.
“I was kind of blown away by what appears to be very irate reaction,” she said. “And I’m not sure if everyone has truly read the article for what it is. It’s an article that suggests, let’s be aware of this, let’s be proactive in this. I don’t think anybody, any physician of color, would say, ‘Gee, this is earthshaking news.’”